So get a character that hasn't done the quest, load up the first mission with the blade of crota and suff. Start the mission and halfway through it, delete the bounty/quest and complete the mission (this way u can repeat the mission). At the end of it you'll get blue tdb engrams. Any engrams that came off enemies during the mission are how engrams. *u can also crank up the difficulty to the highest one to grind xp (gives 7000xp I think) And u can also do the other mission where u destroy the soul of crota I think but the first mission is the easiest